添加 0202.快乐数 Rust版本

添加 0202.快乐数 Rust版本

problems/0202.快乐数.md

@@ -315,6 +315,36 @@ class Solution {
 }
 ```
 
+Rust:
+```Rust
+use std::collections::HashSet;
+impl Solution {
+    pub fn get_sum(mut n: i32) -> i32 {
+        let mut sum = 0;
+        while n > 0 {
+            sum += (n % 10) * (n % 10);
+            n /= 10;
+        }
+        sum
+    }
+
+    pub fn is_happy(n: i32) -> bool {
+        let mut n = n;
+        let mut set = HashSet::new();
+        loop {
+            let sum = Self::get_sum(n);
+            if sum == 1 {
+                return true;
+            }
+            if set.contains(&sum) {
+                return false;
+            } else { set.insert(sum); }
+            n = sum;
+        }
+    }
+}
+```
+
 C:
 ```C
 typedef struct HashNodeTag {